Methods for the Synthesis of Single-Wall Nanotubes for Energetic Applications

Abstract

Single-walled nanotubes for use as additives in energetic materials, and methods for synthesizing such materials are described. The single-walled carbon nanotube (SWNT) additives comprise a mixture of high-purity SWNT and carbon encapsulated iron nanoparticles. The SWNT mixtures may comprise no more than 5% non-SWNT carbon, and the iron nanoparticles may be from 2-5 nm. The method of synthesizing the SWNTs may comprise a high-pressure carbon monoxide (HiPCO) process. The SWNT mixtures may be adapted for use as additives in energetic processes, such as, for example, rocket motors.

What is claimed is: 
     
         1 . A combustion catalyst comprising a mixture of high-purity single-walled carbon nanotubes and non-oxidizable metallic nanoparticles. 
     
     
         2 . The combustion catalyst of  claim 1 , wherein the no more than 5% of the carbon is non-single-walled carbon nanotubes. 
     
     
         3 . The combustion catalyst of  claim 1 , wherein the metallic nanoparticles are from 2 to 5 nm in dimension. 
     
     
         4 . The combustion catalyst of  claim 1 , wherein the metallic nanoparticles are carbon encapsulated iron. 
     
     
         5 . The combustion catalyst of  claim 4 , wherein the metallic nanoparticles are encapsulated in a carbon fullerene material. 
     
     
         6 . The combustion catalyst of  claim 1 , wherein the metallic nanoparticle comprise no greater than 20% of the mass of the mixture. 
     
     
         7 . The combustion catalyst of  claim 1 , wherein the single-walled carbon nanotubes comprise at least 95% of the mass of carbon, wherein the metallic nanoparticles are carbon encapsulated iron comprising no greater than 20% of the mass of the mixture. 
     
     
         8 . A rocket motor opacifier comprising a mixture of high-purity single-walled carbon nanotubes and non-oxidizable metallic nanoparticles. 
     
     
         9 . The opacifier of  claim 8 , wherein the no more than 5% of the carbon is non-single-walled carbon nanotubes. 
     
     
         10 . The opacifier of  claim 8 , wherein the metallic nanoparticles are from 2 to 5 nm in dimension. 
     
     
         11 . The opacifier of  claim 8 , wherein the metallic nanoparticles are carbon encapsulated iron. 
     
     
         12 . The opacifier of  claim 11 , wherein the metallic nanoparticles are encapsulated in a carbon fullerene material. 
     
     
         13 . The opacifier of  claim 8 , wherein the metallic nanoparticle comprise no greater than 20% of the mass of the mixture. 
     
     
         14 . The opacifier of  claim 8 , wherein the single-walled carbon nanotubes comprise at least 95% of the mass of carbon, wherein the metallic nanoparticles are carbon encapsulated iron comprising no greater than 20% of the mass of the mixture. 
     
     
         15 . A method of synthesizing a combustion catalyst comprising:
 introducing a source of carbon and an organometallic catalyst into a reactor at high pressure;   heating the reactor to a reaction temperature such that the organmetallic catalyst decomposes to form metallic nanoparticles; and   reacting the source of carbon with the metallic nanoparticles such that the carbon nucleates on the metallic nanoparticles to form a mixture of high-purity single-walled carbon nanotubes and non-oxidizable metallic nanoparticles.   
     
     
         16 . The method of  claim 15 , wherein the source of carbon is selected from the group of benzene, acetylene, CO, and a mixture of CO and hydrogen. 
     
     
         17 . The method of  claim 15 , wherein the organometallic catalyst is an iron-containing molecule. 
     
     
         18 . The method of  claim 17 , wherein the iorn-containing molecule is ferrocene. 
     
     
         19 . The method of  claim 15 , wherein the pressure in the reactor during reaction is from 30-100 atm, and the temperature is at least 1050° C. 
     
     
         20 . The method of  claim 15 , wherein the single-walled carbon nanotubes comprise at least 95% of the mass of carbon in the mixture, and wherein the metallic nanoparticles are carbon encapsulated iron comprising no greater than 20% of the mass of the mixture.